Why are results based on Gun Time and not Net Time?
The results are based on Gun Time as per the IAAF (International Association of Athletics Federations) rule 165 part 24 (below). The Blackmores Sydney Running Festival is run under these rules because its results can be used for selection into International and Olympic events.
However, net times are also provided for participants who would like to know the true (net) time it took for them to run from the start line to the finish line. This is provided for personal use only.
24. The use of Transponder Timing Systems approved by IAAF in events held under Rules 230 (races not held completely in the stadium), 240 and 250 is permitted provided that:
(a) None of the equipment used at the start, along the course or at the finish line constitutes a significant obstacle or barrier to the progress of an athlete.
(b) The weight of the transponder and its housing carried on the athletes’ uniform, bib or shoe is not significant.
(c) The System is started by the Starter’s gun or synchronised with the start signal.
(d) The System requires no action by an athlete during the competition, at the finish or at any stage in the result processing.
(e) The resolution is 1/10th of a second (i.e. it can separate athletes finishing 1/10th of a second apart). For all races, the time shall be read to 1/10th of a second and recorded to the whole second. All read times not ending in zero shall be converted and recorded to the next longer whole second, e.g. for the Marathon, 2:09:44.3 shall be recorded as 2:09:45.
Note: The official time shall be the time elapsed between the firing of the starting gun and the athlete reaching the finish line.
However, the time elapsed between an athlete crossing the start line and the finish line can be made known to him, but will not be considered an official time.